–I could peek into the safe inserting a small lamp. Surprise! Inside I can see…. a large key!
From what I see and from the marks I got during my impressioning, the key is probably that of lock B.
This means, that maybe lock B is not locked at all.
Or maybe it is, and what I see is a spare key that was left within the safe. And of course, the hole is too small to get the key… and I do not want to widen it further
The plot thickens.
This is the best image I could take of the key through the hole.
(If only I had a fiberscope ! )